Network devices, such as cellular phones, laptop computers, tablets, and wearable devices, include semiconductor components. Examples of the semiconductor components are power converters, analog-to-digital converters, and digital-to-analog converters. Each of the semiconductor components can include a comparator.
As an example, a power management converter can convert a received first direct current (DC) voltage (e.g., 5 volts (V)) to a second DC voltage (e.g., 1.2 V). The power management converter includes a comparator. The comparator receives and compares a first input voltage and a second input voltage to generate a control signal. The first input voltage is representative of the first DC voltage. The second input voltage is representative of the second DC voltage. The second DC voltage is fed back via a feedback loop to generate the second input voltage. The control signal controls a state of a transistor, which in turn sets the second DC voltage (or output voltage) of the power management converter.
The first DC voltage can be pulse-width-modulated (PWM) to generate a stable voltage (i.e. second DC voltage) after an inductor/capacitor (LC) filter network. The feedback loop senses the second DC voltage and compares the second DC voltage to a reference voltage (i.e. Vref) to generate a stable voltage Vcomp via a compensation network. The stable voltage Vcomp is then compared to a first DC voltage supply current information to generate a duty-cycled control signal VCTRL via the comparator. As a result, input signals of the comparator change at certain duty cycles and frequencies. The duty cycles and frequencies are based on (i) DC values of the first DC voltage and second DC voltage, (ii) the load current of the 2nd voltage rail, and (iii) a speed at which an output of the comparator changes relative to changes in the input voltages. A comparator that is capable of responding quickly to changes in the input voltages or load current on output voltage may provide a highly-accurate voltage output.